Safety standards have been developed for electrical outlets used in various applications, to control the delivery of power to an outlet and particularly to ensure that a human body cannot activate the outlet. (An outlet with a safety feature that shuts off power when a human body is detected is said to “exclude the human body model.”) A typical safety standard requires that an isolated sense circuit be provided in the outlet unit to determine that a user device (e.g. an adapter) is plugged in, before enabling the output power. A conventional arrangement uses non-isolated feedback to detect when a device is plugged in, and performs continuous monitoring to ensure that the device remains installed in the outlet.
A number of conventional power outlet safety designs rely on contacts in the outlet to monitor whether a proper plug is installed. For example, one typical outlet has two plunger-actuated sense contacts to detect when a plug is installed. This requires sensing contacts and switches to actuate the output power. Such mechanical sensing and switching arrangements are inherently prone to failure over time.
Accordingly, it is desirable to implement a load detector/analyzer and control device for a power outlet that does not rely on switching or sensing devices within the outlet.